I have to make sortable table like this:
Sortable table:
building_id | building_age | title |
-------------------------------------------------
1 | 100 | New york buil |
2 | 50 | House 1 |
3 | 50 | House 10 |
From these tables:
Building Table:
building_id | building_age | building_type_1_FK | building_type_2_FK
---------------------------------------------------------
1 | 100 | null | 1
2 | 50 | 1 | null
3 | 50 | 2 | null
building_type_1:
type_id | title | diff1 |
-------------------------------------------------
1 | New york buil| blablabla |
building_type_2:
building_id | title |
----------------------------
1 | House 1 |
2 | House 10 |
3 | House 500 |
While joining these tables I get several title columns where one of them is not null. Is there any way to sort by title and select top 10 results without fetching all the data and then sorting in the app?
p.s.. I know that in general this architecture is not good, but I can't change it.
Yes. You want to do a left outer join to the two tables, and then bring the results together:
select b.building_id, b.building_age, coalesce(bt1.title, bt2.title) as title
from building b left outer join
building_type_1 bt1
on b.building_type_1_FK = bt1.type_id left outer join
building_type_2 bt2
on b.building_type_2_FK = bt2.building_id;
To get the top 10 results in Oracle:
select *
from (select b.building_id, b.building_age, coalesce(bt1.title, bt2.title) as title
from building b left outer join
building_type_1 bt1
on b.building_type_1_FK = bt1.type_id left outer join
building_type_2 bt2
on b.building_type_2_FK = bt2.building_id
order by title
) b
where rownum <= 10;
Related
I have three tables store, gender, age_group each of these tables have ids. I need to generate table data for each one all possible combinations of the three.
ex. store_id = (1,2,3) gender_id = (1,2,3) age_group_id = (1,2,3)
so that i have a table that looks like this:
|store_id|gender_id|age_group_id|
|:------:|:-------:|:----------:|
| 1 | 1 | 1 |
| 1 | 2 | 1 |
| 1 | 3 | 1 |
| 2 | 1 | 3 |
| 2 | 2 | 3 |
| 3 | 1 | 3 |
| 3 | 2 | 3 |
etc. continuing on until each combination is populated, any suggestions on best approach to do this in SQL
Cross join the three tables:
select
s.Id as store_id,
g.Id as gender_id,
a.Id as age_group_id
from store s
cross join gender g
cross join age_group a
I have two tables filled with two files of which table1 always has one row more than the second.
I want to merge the two tables into one. When I use a right join e.g.
select *
from table2
right join table1 on table1.id = table2.id and table1.eq_nb = table2.eq_nb
I will have the 4 combinations for eq_nb = 25 because it is repeated two times.
But I rather want to stick the columns side by side
To know, I don't have conditions on arrival and depart time of each eq_nb (I can't add something like datediff(second,table1.arrival_time,table2.depart_time) < X )
table1:
id | eq_nb | arival_time
-------------------------------------
1 | 25 | 05:30:15.231
-------------------------------------
2 | 50 | 06:30:15.231
-------------------------------------
3 | 7 | 07:30:15.231
-------------------------------------
1 | 25 | 08:30:15.231
-------------------------------------
5 | 27 | 09:30:15.231
-------------------------------------
table2:
id | eq_nb | depart_time
----------------------------------
1 | 25 | 05:31:15.231
----------------------------------
2 | 50 | 06:31:15.231
----------------------------------
3 | 7 | 07:31:15.231
----------------------------------
1 | 25 | 08:31:15.231
----------------------------------
desired result:
id | eq_nb | arrival_time | depart_time
-------------------------------------------------------
1 | 25 | 05:30:15.231 | 05:31:15.231
-------------------------------------------------------
2 | 50 | 06:30:15.231 | 06:31:15.231
-------------------------------------------------------
3 | 7 | 07:30:15.231 | 07:31:15.231
-------------------------------------------------------
1 | 25 | 08:30:15.231 | 08:31:15.231
--------------------------------------------------------
5 | 27 | 09:30:15.231 | NULL
--------------------------------------------------------
left join should do what you want:
select *
from table1 t1 left join
table2 t2
on t1.id = t2.id and t1.eq_nb = t2.eq_nb;
Given your data, the ids are unique, so there should be no duplication. Note: This is equivalent to your first query; left join is typically easier to follow because all the rows in the first table are in the result set.
Here is a db<>fiddle, illustrating that it works.
I have a question about JOIN.
TABLE A | TABLE B |
-----------------------------------------|
PK | div | PK | div | val |
-----------------------------------------|
A | a | 1 | a | 10 |
B | b | 2 | a | 100 |
C | c | 3 | c | 9 |
------------------| 4 | c | 99 |
-----------------------
There are two tables something like above, and I have been trying to join two tables but I want to see all rows from TABLE A.
Something like
SELECT T1.PK, T1.div, T2.val
FROM A T1
LEFT OUTER JOIN B T2
ON T1.div = T2.div
and I want the result would look like this below.
PK | div | val |
-------------------------
A | a | 10 |
A | a | 100 |
B | null | null |
C | c | 9 |
C | c | 99 |
I have tried all JOINs I know but B doesn't appear because it doesn't exist. Is it possible to show all rows on TABLE A and just show null if it doesn't exists on TABLE B?
Thanks in advance!
If you change your query to
SELECT T1.PK, T2.div, T2.val
FROM A T1
LEFT OUTER JOIN B T2
ON T1.div = T2.div
(Note, that div comes from T2 here.), you'll get exactly the result posted (but maybe in a different order, add an ORDER BY clause if you want a specific order).
Your query as it stands will get you:
PK | div | val |
-------------------------
A | a | 10 |
A | a | 100 |
B | b | null |
C | c | 9 |
C | c | 99 |
(Note, that div is b for the row with the PK of B, not null.)
To get to your resultset, all you need to do is use T2.Div as that is the value that does not exist in the second table:
SELECT T1.PK, T2.div, T2.val
FROM A T1
LEFT OUTER JOIN B T2
ON T1.div = T2.div
So I am wondering. I fell into an interesting suggestion from another developer. So i basically have two tables I join in a query and I want the resulting table from the query to have an extra column that comes from the table on from the joint.
Example:
#table A: contains rating of players, changes randomly at any date depending
#on drop of form from the players
PID| Rating | DateChange |
1 | 2 | 10-May-2014 |
1 | 4 | 20-May-2015 |
1 | 20 | 1-June-2015 |
2 | 4 | 1-April-2014|
3 | 4 | 5-April-2014|
2 | 3 | 3-May-2015 |
#Table B: contains match sheets. Every player has a different match sheet
#and plays different dates.
MsID | PID | MatchDate | Win |
1 | 2 | 10-May-2014 | No |
2 | 1 | 15-May-2015 | Yes |
3 | 3 | 10-Apr-2014 | No |
4 | 1 | 21-Apr-2015 | Yes |
5 | 1 | 3-June-2015 | Yes |
6 | 2 | 5-May-2015 | No |
#I am trying to achieve this by running the ms-access query: i want to get
#every players rating at the time the match was played not his current
#rating.
MsID | PID | MatchDate | Rating |
1 | 2 | 10-May-2014 | 4 |
2 | 1 | 15-May-2015 | 2 |
3 | 3 | 10-Apr-2014 | 4 |
4 | 1 | 21-Apr-2015 | 4 |
5 | 1 | 3-June-2015 | 20 |
6 | 2 | 5-May-2015 | 3 |
This is what I have tried below:
Select MsID, PID, MatchDate, A-table.rating as Rating from B-table
left Join A-table
on B-table.PID = A-table.PID
where B-table.MatchDate > A-table.Datechange;
any help is appreciated. The solution can be in Vba as long as it returns something like a view/table I can manipulate using other queries or report.
Think of this in terms of sets of data... you need a set that lists the MAX dateChange for each player's and match date.
Soo...
SELECT MAX(A.DateChange) MDC, A.PID, B.Matchdate
FROM B-table B
INNER Join A-table A
on B.PID = A.PID
and A.DateChange <= B.MatchDate
GROUP BY A.PID, B.Matchdate
Now we take this and join it back to what you've done to limit the results in table A and B to ONLY those with that date player and matchDate (my inline table C)
SELECT B.MsID, B.PID, B.MatchDate, A.rating as Rating
FROM [B-table] B
INNER JOIN [A-table] A
on B.PID = A.PID
INNER JOIN (
SELECT MAX(Y.DateChange) MDC, Y.PID, Z.Matchdate
FROM [B-table] Z
INNER Join [A-table] Y
on Z.PID = Y.PID
and Y.DateChange <= Z.MatchDate
GROUP BY Y.PID, Z.Matchdate) C
on C.mdc = A.DateChange
and A.PID = C.PId
and B.MatchDate = C.Matchdate
I didn't create a sample for this using your data so it's untested but I believe the logic is sound...
Now Tested! SQL Fiddle using SQL server though...
My results don't match yours exactly. I think you're expected results are wrong though for MSID 4 given rules defined.
I have three tables
Prospect -- holds prospect information
id
name
projectID
Sample data for Prospect
id | name | projectID
1 | p1 | 1
2 | p2 | 1
3 | p3 | 1
4 | p4 | 2
5 | p5 | 2
6 | p6 | 2
Conjoint -- holds conjoint information
id
title
projectID
Sample data
id | title | projectID
1 | color | 1
2 | size | 1
3 | qual | 1
4 | color | 2
5 | price | 2
6 | weight | 2
There is an associative table that holds the conjoint values for the prospects:
ConjointProspect
id
prospectID
conjointID
value
Sample Data
id | prospectID | conjointID | value
1 | 1 | 1 | 20
2 | 1 | 2 | 30
3 | 1 | 3 | 50
4 | 2 | 1 | 10
5 | 2 | 3 | 40
There are one or more prospects and one or more conjoints in their respective tables. A prospect may or may not have a value for each conjoint.
I'd like to have an SQL statement that will extract all conjoint values for each prospect of a given project, displaying NULL where there is no value for a value that is not present in the ConjointProspect table for a given conjoint and prospect.
Something along the lines of this for projectID = 1
prospectID | conjoint ID | value
1 | 1 | 20
1 | 2 | 30
1 | 3 | 50
2 | 1 | 10
2 | 2 | NULL
2 | 3 | 40
3 | 1 | NULL
3 | 2 | NULL
3 | 3 | NULL
I've tried using an inner join on the prospect and conjoint tables and then a left join on the ConjointProspect, but somewhere I'm getting a cartesian products for prospect/conjoint pairs that don't make any sense (to me)
SELECT p.id, p.name, c.id, c.title, cp.value
FROM prospect p
INNER JOIN conjoint c ON p.projectID = c.projectid
LEFT JOIN conjointProspect cp ON cp.prospectID = p.id
WHERE p.projectID = 2
ORDER BY p.id, c.id
prospectID | conjoint ID | value
1 | 1 | 20
1 | 2 | 30
1 | 3 | 50
1 | 1 | 20
1 | 2 | 30
1 | 3 | 50
1 | 1 | 20
1 | 2 | 30
1 | 3 | 50
2 | 1 | 10
2 | 2 | 40
2 | 1 | 10
2 | 2 | 40
2 | 1 | 10
2 | 2 | 40
3 | 1 | NULL
3 | 2 | NULL
3 | 3 | NULL
Guidance is very much appreciated!!
Then this will work for you... Prejoin a Cartesian against all prospects and elements within that project via a select as your first FROM table. Then, left join to the conjoinprospect. You can obviously change / eliminate certain columns from result, but at least all is there, in the join you want with exact results you are expecting...
SELECT
PJ.*,
CJP.Value
FROM
( SELECT
P.ID ProspectID,
P.Name,
P.ProjectID,
CJ.Title,
CJ.ID ConJointID
FROM
Prospect P,
ConJoint CJ
where
P.ProjectID = 1
AND P.ProjectID = CJ.ProjectID
ORDER BY
1, 4
) PJ
LEFT JOIN conjointProspect cjp
ON PJ.ProspectID = cjp.prospectID
AND PJ.ConjointID = cjp.conjointid
ORDER BY
PJ.ProspectID,
PJ.ConJointID
Your cartesian product is a result of joining by project Id - in your sample data there are 3 prospects with a project id of 1 and 3 conjoints with a project id of 1. Joining based on project id should then result in 9 rows of data, which is what you're getting. It looks like you really need to join via the conjointprospects table as that it what holds the mapping between prospects and conjoint.
What if you try something like:
SELECT p.id, p.name, c.id, c.title, cp.value
FROM prospect p
LEFT JOIN conjointProspect cp ON cp.prospectID = p.id
RIGHT JOIN conjoint c ON cp.conjointID = c.id
WHERE p.projectID = 2
ORDER BY p.id, c.id
Not sure if that will work, but it seems like conjointprospects needs to be at the center of your join in order to correctly map prospects to conjoints.